Controlled power switch modules are well known in the art. They are found in the form of, for example, insulated gate bipolar transistors (IGBT), metal-oxide-semiconductor field-effect transistor (MOSFET) and bi-polar transistors.
Controlled power switch modules are usually provided with two input tab connections designed to be connected to a DC (direct current) source and at least one output tab connection designed to provide an AC (alternating current) output. One or more modules are conventionally used, for example, in DC to AC converters.
Each module is provided with one, two or more controlled power switches, one, two or more diodes and possibly other passive components such as resistors and diodes.
Furthermore, with the limited space allowed for the power inverter circuits in electric and/or electric hybrid automotive applications and the high cost of the semiconductors, the demand for integration of power electronics increases.
A known way of reducing the space occupied by the semiconductors in vehicles inverters is to increase their efficiency to allow the size of the cooling surface to be reduced.
The losses in controlled power switch modules present in conventional inverter designs are mainly caused by two sources; conduction losses and switching losses. One way to improve controlled power switch module switching losses is generally by accelerating the controlled power switch turn-on and turn-off. However, with faster controlled power switch turn-off, the overvoltage due to the parasitic inductance of the high-frequency loop increases so much that slow down of the turn-off is often required to protect the device, thereby seriously impacting the efficiency of the inverter.
The power that can deliver the converter is related to the maximum operating voltage and the maximum output current. Limiting the overvoltage across the controlled power switch allows the operation at a higher voltage and then provides higher power.